Quick opening pressure manhole



Oct. 5, 1965 J. H. DE FREES 3,209,938

QUICK OPENING PRESSURE MANHOLE Sheets-Sheet 1 Filed June 20, 1965 v f 24 /3d- I. 36 l 22 zz /3 I /3 INVENTOR. Jbsnw h. Lk/ FFFES Z7 5 Nix Oct. 5, 1965 J. H. DE FREES 3,209,938

QUICK OPENING PRESSURE MANHOLE 3 Sheets-Sheet 2 Filed June 20, 1963 INVENTOR. JosEPH hf DEfiE/ifi 197" TOR/YE 5 Sheets-Sheet I5 VENTOR.

ia r/ Oct. 5, 1965 J. H. DE FREES QUICK OPENING PRESSURE MANHOLE United States Patent 3,209,938 QUICK OPENING PRESSURE MANHOLE Joseph H. De Frees, 414 Liberty St., Warren, Pa. Filed June 20, 1963, Ser. No. 289,176 3 Claims. (Cl. 22055) This invention relates to a safety tank closure, and more particularly to novel and improved quickly-releasable clamping means for attaching such closure to the tank.

In the storage or transportation of flammable or volatile liquids it is quite desirable that the manhole usually provided with each tank section have a securely fitting cover which is leakproof, vapor sealing, and dustproof. Assuming the provision of a cover which meets these requirements, it is further desirable that quickly-releasable clamping means be provided which is not structurally complex, so that an operator can attach or release the clamping means with a minimum loss of time and effort.

An obejct. of the present invention therefore is to provide novel and improved clamping means for securing the manhole cover on a liquid storage or transportation tank.

A further object of the invention is to provide novel and improved clamping means requiring practically no loss of time for its attachment or release.

A further object of the invention is to provide clamping means as defined in the last preceding paragraph which can be readily and economically manufactured but which effects a positive and secure clamping force so as to prevent liquid or vapor from escaping from the tank.

A further object of the invention is to provide clamping means as defined in the last preceding paragraph and including, in combination therewith, novel and improved aligning means for guiding and facilitating application of the clamping means during the cover-securing operation.

Other objects and advantages will be apparent from a study of one embodiment of the invention as disclosed in the following description, in conjunction with the accompanying drawings, in which FIG. 1 is a fragmentary side elevational view of a liquid transportation tank showing a manhole housing ring and cap.

FIG. 2 is a top plan view, somewhat enlarged, as seen from above FIG. 1.

FIG. 3 is a side elevational view as seen from below FIG. 2.

FIGS. 4 and 5 are sectional views taken respectively on the lines 44 and 55 of FIG. '2.

FIG. 6 is an end elevational view as it would appear from the position of the line 66 on FIG. 2.

FIG. 7 is a top plan view with the hinge part broken away, showing the clamping ring in open and rearwardly retracted position.

FIG. 8 is a fragmentary side elevational view partly in section, and similar to FIG. 5, but showing parts in a different operating position.

FIG. 9 is a view similar to FIG. 5, but showing parts in a diflerent operating position.

Speaking first generally, I show in FIG. 1 the rear portion 10 of a liquid transportation vehicle which has one or more manhole assemblies 11. The vehicle is normally divided by bulkheads 12 into a plurality of compartments, each having a manhole, as shown. The manhole assembly 11 includes a cylindrical housing ring 13 and a cap or cover 14 swingably attached to ring 13 as follows. A pair of spaced brackets 15a, 15b are attached to the ring 13 in spaced relationship and a hinge pin 16 spans the space between the brackets. Upturned lugs 15c, 15d on the brackets have aligned apertures in which the hinge pin is journalled. A rearwardly extending arm 17 having a downturned tab 17a cooperates with an angle member 18 to form a box channel enclosing the hinge pin, the angle 18 being welded to arm 17 as shown. The cover is shown swung to partially open position in FIG. 9. A handle 20 is available for manipulation of the cover.

An annular angle ring 21 is welded around the inner face of the top of ring 13 to serve as a seat for gasket 22 and the lower peripheral edge of the cap seats on the gasket in sealing relationship when the cap is in closed position, as best seen in FIG. 5. An annular ring 23 is welded around the outer periphery of cap 14, as shown in FIG. 5, being disposed beneath hinge arm 17. This cooperates with an outturned lip 13a around the upper edge of ring 13 to provide two planar members which can be forced towards each other to secure the cap tightly on the manhole ring 13. This is accomplished as follows.

I provide a clamping ring in three connected segmental sections 24, 25 and 26, as best seen in FIG. 7, sections 25 and 26 being hinged to the opposed ends of section 24 by respective hinges 27 and 28. Directing attention to the left side of FIG. 2, the free ends of respective rings 25 and 26 have outwardly projecting lugs 29 and 30. Lug 30 pivotally carries a swing bolt 31 which is threaded at its free end to receive a wing type nut 32. Bolt 31 is swingable into a clevis in lug 29 when the ring segments 24, 25 and 26 are moved from the open position as shown in FIG. 7 to clamping position as shown in FIG. 2. A spacer sleeve 33 is interposed on bolt 31 and also a contoured ali ning bar 34 which nests in a curved surface portion of lug 29, the assembly being self-aligning as the nut 32 is advanced to final position.

As seen in FIGS. 4, 5, 8 and 9, the clamping ring segments have an inwardly opening groove 37 having an outwardly divergent or cam-like upper surface 37a. As a result, when the three hinged ring segments are moved inwardly from the position of FIG. 7 to the position of FIG. 2 and the assembly is tightened by means of nut 32, the upper and lower groove walls grip the ring flanges 13a and 23, and the cam surface 26a forces ring 23, and consequently cover 14, downwardly so that the lower peripheral edge of the cover indents the gasket 22.

The clamping ring, when disengaged, remains in conveniently available position by reason of the following structural arrangement. The rear ring section 24 rests on the top edge of hinge brackets 15a, 15b (FIG. 7). A slidable plate 38 is welded to the underside of ring section 24 (FIGS. 5, 8 and 9) and its rear lateral edge portions are adapted to slide rearwardly under spacers or shims 39, 40 on hinge pin 16, which spacers retain the said lateral edges of the sliding plate from cocking or tilting upwards.

In the absence of this retention the overhang of ring sections 25 and 26 would cause downward swing of the ring assembly until it came in contact with the tank top, and replacement to clamped position would take a certain amount of jockeying before the groove 37 in the ring could again be brought into registry with flanges 13a and 23 (FIGS. 4 and 5). The sliding plate 38 is retained in the same plane by spacers 39, 40.

The operation of the clamping ring should now be obvious. Assuming the manhole has been in open position the lid is closed, thereby attaining the position shown in FIG. 7. The whole clamping ring is now pulled to the left, so as to engage the groove 37 in ring portion 24 with the flanges 13a and 23. The side segments 25 and 26 are then swung inwardly, somewhat short of the position shown in FIG. 2, and the swing bolt 31 is turned counterclockwise from the position of FIG. 7 to the position shown in FIG. 2 after which the wing nut 32 is twirled to tightened position. The final stages of wing nut rotation pull the cammed surface 37a against the annular flange 23 a so as to close cover 14 to sealed position, as previously described. All three ring segments 24, 25 and 26 are always in the same horizontal plane as the flanges 13a and 23, by reason of the positioning eifect of sliding plate 38, so that the ring can be released or attached even in the dark.

What is claimed is:

1. Clamping means for a collar surrounding and defining a manhole port, comprising a cover, hinge means comprising a pair of spaced lugs carried on said collar, a hinge pin extending between said lugs, a hinge strap extending rearwardly from said cover and adapted to receive said hinge pin, whereby said cover can be swung to and from closed position, said cover and said collar having complementary circumferential flanges with respective peripheral edge portions lying in adjacent parallel planes when the cover is moved to closed position, a peripheral ring clamp composed of a plurality of mutually hinged curved segments, each engageable simultaneously with respective portions of both said circumferential flanges and disposed, by inward contraction, to draw said flanges towards each other whereby to tightly secure said cover on said collar, a ring segment adjacent said hinge means having a planar portion slidably extendable rearwardly between said lugs and under said hinge pin and aligning means carried on said hinge pin and slidably contactable with an upper surface of said planar portion for guiding said ring clamp in its movement to and from clamped position.

2. A clamping means as defined in claim 1 wherein said aligning means consists of a pair of members perforated to be insertible on said hinge pin and disposed one on each side of said hinge strap, and having a lower surface portion in sliding contact with said planar portion.

3. Clamping means for a collar surrounding and defining a manhole port, comprising a cover adapted for disposal in sealing relationship With said collar, said cover and said collar having complementary circumferential flanges with respective peripheral edge portions lying in adjacent parallel planes when the cover is in closed position, a peripheral ring clamp composed of a plurality of mutually hinged curved segments, each engageable simultaneously with respective portions of both said circumferential flanges and disposed, by inward contraction to draw said flanges toward each other whereby to tightly secure said cover on said collar, a pair of lugs on said collar and extending outwardly therefrom, a transverse pin spanning the space between said lugs, a ring segment adjacent said pin having a planar portion slidably extending rearwardly under said pin, and aligning means carried on said pin and slidably contactable with an upper surface of said planar portion for guiding said ring clamp in its movement to and from clamped position.

References Cited by the Examiner UNITED STATES PATENTS 1,958,923 5/34 Mohler 220 2,715,477 8/55 North 220-55 THERON E. CONDON, Primary Examiner.

EARLE J. DRUMMOND, Examiner. 

1. CLAMPING MEANS FOR A COLLAR SURROUNDING DEFINING A MANHOLE PORT, COMPRISING A COVER, HINGE MEANS COMPRISING A PAIR OF SPACED LUGS CARRIED ON SAID COLLAR, A HINGE PIN EXTENDING BETWEEN SAID LUGS, A HINGE STRAP EXTENDING REARWARDLY FROM SAID COVER AND ADAPTED TO RECEIVE SAID HINGE PIN, WHEREBY SAID COVER CAN BE SWUNG TO AND FROM CLOSED POSITION, SAID COVER AND SAID COLLAR HAVING COMPLEMENTARY CIRCUMFERENTIAL FLANGES WITH RESPECTIVE PERIPHERAL EDGE PORTIONS LYING IN ADJACENT PARALLEL PLANES WHEN THE COVER IS MOVED TO CLOSED POSITION, A PERIPHERAL RING CLAMP COMPOSED OF A PLURALITY OF MUTUALLY HINGED CURVED SEGMENTS, EACH ENGAGEABLE SIMULTANEOUSLY WITH RESPECTIVE PORTIONS OF BOTH SAID CIRCUMFERNTIAL FLANGES AND DISPOSED, BY INWARD CONTRACTION, TO DRAW SAID FLANGES TOWARDS EACH OTHER WHEREBY TO TIGHTLY SECURE SAID COVER 